Reference: Hu, H., et al. (1989). "Tear Gas-Harassing Agent or Toxic Chemical Weapon." Jama-Journal of the American Medical Association262(5): 660-663.
Tear gas has gained widespread acceptance as a means of crowd control among the civilian population. Available toxicological data is insufficient to determine the risk of tear gas to cause pulmonary, carcinogenic, and reproductive damage over the long term.
Large amounts of tear gas has been used in various countries around the world.
It is a common name for chemicals called "harassing agents" due to the ability to disable an individual or group temporarily. Two of the most commonly used are w-chloroacetophenone (CN) and o-chlorobenzylidenemalononitrile (CS).
The question of safety is naturally raised due to the widespread usage. The Himsworth Report concluded that while CS gas can be lethal, but only at concentrations that were several hundred times greater that than those that would produce intolerable symptoms.
The Use of Tear Gas in Seoul, South Korea
By the governments account, they had used 351200 tear gas canisters and grenades during the month of June in 1987.
They obtained a sample of the tear gas used and mass spectrometry identified it to be CS gas. Those who stood close to a tear gas canister when it exploded received trauma due to the plastic projectiles created from the explosion. This trauma was made worse by the presence of the CS on the plastic. Some symptoms of the gas were revealed to be cough and shortness of breath.
According to Korean scientists, their government withheld the composition of the gas being used which made analyzing the effects of the gas extremely difficult. They would also avoid trying to analyzing it for fear of being punished.
Exposure to tear gas has been correlated to an increase in the rate of miscarriages and stillbirths.
CS and Other Tear Gas Agents
Poisonous gases have been used by various military factions since 482 B.C. When chemical warfare was advanced during World War I, lacrimation agents such as tear gas became the most popular.
CN gas was originally the most popular as it is the main ingredient in mace. It is chemically unstable though and scientist wanted to pursue other alternatives.
CS was developed in the 1950's as a white powder and is mixed with a pyrotechnic in order to be used. Its most basic form is in that of a cloud or fog and causes severe skin and mucous membrane irritation at even small doses.
It has all but replaced CN in normal use through delivery systems involving cluster bombs or a continuous-spray device.
Toxicology of CS
Military studies believe that after getting away from the gas most symptoms resolve themselves quickly.
High levels of CS inhalation can however cause pneumonitis or pulmonary edema.
CS canisters generate clouds of between 6 to 9m with a concentration of 2000-5000 mg/m^3 where a lethal dose would have to be between 25000 and 150000 mg/m^3.
Enclosed spaced cause a much more concentrated detonation.
Metabolic studies say that CS will metabolize to cyanide.
Debates occur on whether significant amounts of cyanide are generated. Those that dismiss it say that the quantity that would have to be inhaled would be far too massive.
Other symptoms include contact burns and skin sensitization with contact dermatitis.
No significant effect was found when relating tear gas exposure to pregnancy.
Potential for Genotoxicity
CS has the ability to alkylate sulfhydryl groups, like for instance DNA. CS has been shown to be clastogenic while inducing sister chromatids to exchange.
Cs has been found to suppress esterase activity but it has not shown to be tumorigenic.
Toxicity of CN
CN has been deemed to be more toxic than CS since it is more likely to cause permanent corneal damage upon contact with the eye. At least 5 deaths have been reported in relation to the use of CN gas.
Treatment
Exposure to CS and CN gas causes immediate irritation of the eyes and respiratory tract.
Management begins by removing all contaminated clothing, washing the skin with a mild alkaline solution, and a local anesthetic and patch for the eyes.
Patients should be kept under observation for several days with a treatment of humidified oxygen.
Assignment 2: Article Summary
Reference: Hu, H., et al. (1989). "Tear Gas-Harassing Agent or Toxic Chemical Weapon." Jama-Journal of the American Medical Association 262(5): 660-663.
URL: http://desastres.usac.edu.gt/documentos/pdf/eng/doc8080/doc8080-contenido.pdf
Intro
- Tear gas has gained widespread acceptance as a means of crowd control among the civilian population. Available toxicological data is insufficient to determine the risk of tear gas to cause pulmonary, carcinogenic, and reproductive damage over the long term.
- Large amounts of tear gas has been used in various countries around the world.
- It is a common name for chemicals called "harassing agents" due to the ability to disable an individual or group temporarily. Two of the most commonly used are w-chloroacetophenone (CN) and o-chlorobenzylidenemalononitrile (CS).
- The question of safety is naturally raised due to the widespread usage. The Himsworth Report concluded that while CS gas can be lethal, but only at concentrations that were several hundred times greater that than those that would produce intolerable symptoms.
The Use of Tear Gas in Seoul, South Korea- By the governments account, they had used 351200 tear gas canisters and grenades during the month of June in 1987.
- They obtained a sample of the tear gas used and mass spectrometry identified it to be CS gas. Those who stood close to a tear gas canister when it exploded received trauma due to the plastic projectiles created from the explosion. This trauma was made worse by the presence of the CS on the plastic. Some symptoms of the gas were revealed to be cough and shortness of breath.
- According to Korean scientists, their government withheld the composition of the gas being used which made analyzing the effects of the gas extremely difficult. They would also avoid trying to analyzing it for fear of being punished.
- Exposure to tear gas has been correlated to an increase in the rate of miscarriages and stillbirths.
CS and Other Tear Gas Agents- Poisonous gases have been used by various military factions since 482 B.C. When chemical warfare was advanced during World War I, lacrimation agents such as tear gas became the most popular.
- CN gas was originally the most popular as it is the main ingredient in mace. It is chemically unstable though and scientist wanted to pursue other alternatives.
- CS was developed in the 1950's as a white powder and is mixed with a pyrotechnic in order to be used. Its most basic form is in that of a cloud or fog and causes severe skin and mucous membrane irritation at even small doses.
- It has all but replaced CN in normal use through delivery systems involving cluster bombs or a continuous-spray device.
Toxicology of CS- Military studies believe that after getting away from the gas most symptoms resolve themselves quickly.
- High levels of CS inhalation can however cause pneumonitis or pulmonary edema.
- CS canisters generate clouds of between 6 to 9m with a concentration of 2000-5000 mg/m^3 where a lethal dose would have to be between 25000 and 150000 mg/m^3.
- Enclosed spaced cause a much more concentrated detonation.
- Metabolic studies say that CS will metabolize to cyanide.
- Debates occur on whether significant amounts of cyanide are generated. Those that dismiss it say that the quantity that would have to be inhaled would be far too massive.
- Other symptoms include contact burns and skin sensitization with contact dermatitis.
- No significant effect was found when relating tear gas exposure to pregnancy.
Potential for Genotoxicity- CS has the ability to alkylate sulfhydryl groups, like for instance DNA. CS has been shown to be clastogenic while inducing sister chromatids to exchange.
- Cs has been found to suppress esterase activity but it has not shown to be tumorigenic.
Toxicity of CN- CN has been deemed to be more toxic than CS since it is more likely to cause permanent corneal damage upon contact with the eye. At least 5 deaths have been reported in relation to the use of CN gas.
Treatment